Mobile communication devices may include a variety of components including circuit boards, integrated circuit (IC) devices and/or System-on-Chip (SoC) devices. The components may include processing devices, user interface components, storage and other peripheral components that communicate through a shared data communication bus, which may include a serial bus or a parallel bus. General-purpose serial interfaces known in the industry, including the Inter-Integrated Circuit (I2C or I2C) serial bus and its derivatives and alternatives, such as interfaces defined by the Mobile Industry Processor Interface (MIPI) Alliance, including the I3C interface, the system power management interface (SPMI), and the Radio Frequency Front-End (RFFE) interface.
In one example, the I2C serial bus is a serial single-ended computer bus that was intended for use in connecting low-speed peripherals to a processor. Some interfaces provide multi-master buses in which two or more devices can serve as a bus master for different messages transmitted on the serial bus. In another example, the RFFE interface defines a communication interface for controlling various radio frequency (RF) front-end devices, including power amplifier (PA), low-noise amplifiers (LNAs), antenna tuners, filters, sensors, power management devices, switches, etc. These devices may be collocated in a single integrated circuit (IC) device, or provided in multiple IC devices. In a mobile communications device, multiple antennas and radio transceivers may support multiple concurrent RF links.
In an SOC there can be systems in different chipsets that need to communicate with each other in real-time. One system may provide the other systems awareness of its state using coexistence messages. Coexistence messages are transmitted a multisystem platform to prevent or reduce instances of systems impinging on each other. In many instances, coexistence messages are transmitted over dedicated point-to-point links. These point-to-point links consume precious general-purpose input/output (GPIO) pins within the mobile communication devices and it would be desirable to reduce the number of physical pins needed to carry coexistence information and other low-level signal information or messages.